From 6dca4ac6fc91fd41ea4d6c4511838d37f4e0eab2 Mon Sep 17 00:00:00 2001 From: Peter Collingbourne Date: Mon, 22 May 2023 17:43:08 -0700 Subject: [PATCH] mm: call arch_swap_restore() from do_swap_page() Commit c145e0b47c77 ("mm: streamline COW logic in do_swap_page()") moved the call to swap_free() before the call to set_pte_at(), which meant that the MTE tags could end up being freed before set_pte_at() had a chance to restore them. Fix it by adding a call to the arch_swap_restore() hook before the call to swap_free(). Link: https://lkml.kernel.org/r/20230523004312.1807357-2-pcc@google.com Link: https://linux-review.googlesource.com/id/I6470efa669e8bd2f841049b8c61020c510678965 Fixes: c145e0b47c77 ("mm: streamline COW logic in do_swap_page()") Signed-off-by: Peter Collingbourne Reported-by: Qun-wei Lin Closes: https://lore.kernel.org/all/5050805753ac469e8d727c797c2218a9d780d434.camel@mediatek.com/ Acked-by: David Hildenbrand Acked-by: "Huang, Ying" Reviewed-by: Steven Price Acked-by: Catalin Marinas Cc: [6.1+] Signed-off-by: Andrew Morton --- mm/memory.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/mm/memory.c b/mm/memory.c index 0ae594703021..01f39e8144ef 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -3950,6 +3950,13 @@ vm_fault_t do_swap_page(struct vm_fault *vmf) } } + /* + * Some architectures may have to restore extra metadata to the page + * when reading from swap. This metadata may be indexed by swap entry + * so this must be called before swap_free(). + */ + arch_swap_restore(entry, folio); + /* * Remove the swap entry and conditionally try to free up the swapcache. * We're already holding a reference on the page but haven't mapped it